Pole-changer.



No. 728,372. u PATENTED MAY 19, 190s J. CRAWFORD.

POLE CHANGER.

APPLICATION MLPD APR. 26, 1902. A

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N0. 728,372. i PATENTED MAY 19, 1903.

J. CRAWFORD. POLE CHANGER.

APPLICATION FILED APB.. 26, 1902. v I0 IODEL. I I 3 BHBBTBBHEET 2.

` No. 728,372. I PATRNTRD MAY 19, 1920.3.

J. CRAWFORD.

PoLR CHANGER.

APPLIOTION FILED APR. 26. 1902.

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JOIIN=ORAWFORD, O'F DENVER, COLORADO.

POLE-CHANGER.-

srncrFrcAT-on foi-ming pari pf- Letters' Patent No. 728,372, dated May' i9, 190e.

.Application irai April ze, 1902. seria No. 104,862. iNo modei.)

To all whom 7125 may concern: I

Be it known that I, ,1 oHVN CRAWFORD, a citizen of t-he UnitedA States of America, residing at Denver, in the county of Arapahoe and State of Colorado, have inventedcertain new and useful Improvements in Pole-Changers; and I do declare the following to be a full,

clear, and exact description of the invention,

such as will enable others skilled in the art to which it appertains to make and use the same, reference being had tothe accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in that class of electrical devices known as pole-changers; .and the objects of my invention are, first, to provide means for alternately switching the poles to a source of electricity in a circuit, so that successively positive and negative currents of any desired frequency are sent to the line and operate to ring a polarized bell, as in telephony, or for any other purpose Where alternating currents are desired; second, to provide means' for delivering or sending to line a series of pulsating direct currents of positive and negative polarity, respectively, for use in socalled party-line or selectivei signaling in telephony where more than one instrument with armatures biased and only responding to pulsating positive or negative currents may be connected on one circuit and signals sent to either instrument without affecting the others. I attain these objects by the mechanism illustrated in the accompanying drawings, in which-- Figure l is a plan view ofthe common form of pole-changer, showing the application of my invention to it. Fig. 2 is a plan view of a pole-changer embodying a simpler and more compact mechanical arrangement of my invention than that shown in Fig. l. Fig. 3 is a perspective View of the armature of Fig. 2. Fig. 4 is a cross-section ofthe armature shown in Figs. 2 and 3. Figo is a plan view of a pole-changer embodying the preferred construction of my invention. Fig. 6 is an end elevation of Fig. 5, and Fig. 7 is a perspective view of the cylinder shown in Figs. 5 and (3.

Similar characters of reference refer to similar par-ts throughout the several Views.

Referring to the drawings, the numeral 1 designates a supporting base-plate, to which I 'secu re an electromagnet 2 by screws 3. The magnet is provided with a projecting core et. An armature 5 is arranged in operative relation to the core of the magnet. The armature is provided with an insulated eX- tension 6, to the free end portion of which I secure two contact-pins 7 and 8. contact-pins Iconnect by insulated wire connections 9 and 10 with the binding-posts 11 and 12. Short coils 13 and 14 are inserted in the connections 9 and l0, respectively, to allow free movement of the armature. The electromagnet 2, including the make-andbreak mechanism described below, is connected by wires 15 and 16 to the bindingposts 17 and 18, which are 'connected to a battery 19 by wires 2O and 21. The bindingposts 11 and 12 are connected by Wires 22 and 23 ito a group of batteries 24, preferably Jifty or more cells being used. A spring 25 extends from the armature 5 to a post 27, which is connected by a wire 28 to the electromagnet. the magnets core is provided with a contactterminal 29. One end of a spring 30 is arranged in operative relation to the contactterminal 29, While the opposite end is connected to the contact-post 31, thus completing the circuit from the battery 19 to the elect-romagnet and through the'armature 5 and contact-post 27 and contact 29 and the spring 30 and contact-post 31 back to the battery 19. This circuit keeps the armature 5 vibrating constantly as the circuit is closed or broken by the armatures making or breaking the circuit with theV electromagnet, as is done in an ordinary vibrating bell.

32 designates a binding-post. A contactterminal spring 33 is secured at one end to the binding-post 32 and is arranged with its opposite end in operative make-and-break relation to the adjacent end 7"* of the contactpin 7.

34 also designates a binding-post, to which one end of a contact-spring 35 is secured, the opposite end of which is arranged in makeand-break relation to the adjacent end 7 of These two j The end of the armature adjacent to IOO the contact-pin 7. A conductive wire 36 is connected at one end to the binding-post 32 and extends to a binding-post 37. A conductive wire 38 is connected at one end to the binding-post 34 and extends to a bindingpost 39.

A contact-spring 40 is arranged with one end in make-and-break relat-ion to the end 3A of the contact-pin 8. The opposite end of this contact-spring is secured to a binding-post 4l. A contact-spring 42 is also arranged with one end in make-and-break relation to the end 8B of the pin 8, and the opposite end of the contact-spring 42 is secured to a bindingpost 43. A conductive wire 44 is connected to the binding-post 43 and connects to the Wire 36. A conductive wire 45 also extends from the binding-post 43 to a contact-pin 46, which is located adjacent to the pins 7 and S. This contact-pin is also arranged with two terminal ends,with one end 46A of which one end of a contact-spring 47 is arranged in makeand-break cont-act. The opposite end of the contact-spring 47 is supported by the contactpost 48. A conductive wire 49 extends from the contact-pcst48 to a binding-post 50. One end of a contact-spring 5l is also arranged in make-and-break relation to the opposite end 46B of the contact-pin 46. The opposite end of this contact-spring is supported by the binding-post 52. A conductive Wire 53 extends from the binding-post 52 to a bindingpost 54. By means of this device as arranged in Fig. l alternating currents and a series of pulsating direct currents of positive and negative polarity are produced simultaneously as follows: The armature is kept constantly vibratingin make-and-break order by the current owing through the electric magnet and through the make-and-break circuit. Then if the battery is so connected that the negative pole goes to ll andthe positive to l2 then the contact-pin 3 will be positive and the contact 7A will be negative, and when the armature 5 is attract-ed by electromagnet the pins 7A and 8A will be brought into momentary contact with springs 33 and 4G, when a positive current will flow to binding-post 39 and a negative current will flow to 37, and When the armature 5 is brought back by its spring the contact between the pins 7A and 3A will be broken and a contact will be made between the pins 7B and 8B and springs 35 and 42, when a positive current will flow to binding-post 37 and a negative current to binding-post 39. Thus alternating currents may be obtained by making connection with 39 and 37, and this particular part of the mechanism may be used for signaling in telephony Where ordinary polarized bells are used. Thus the binding-posts 43 and 32, also 34 and 4l, are alternately connected to the negative and positive poles ofthe main battery 24. It follows that whatever the polarityof the binding-post 43 may be or its corresponding contact 32 at any part of the stroke the ends 46A and 46B of pin 46 will be of the same polarity and will deliver currents of this polarity either through spring 5l or through spring 47 to the binding-posts 50 and 54. Thus When armature 5 is attracted to the core of magnet and a circuit is formed a negative current flows from pin 7A to spring 33, post 32 to post 37, and also through branch Wire 44 to post 43, through Wire 45 to the supplementary pin 46, to spring 47, to post 4S, and from post 48 through wire 49 to binding-post 50, and when the armature 5 is returned by its spring and the circuit is broken with 7A and a contact is formed with SB a positive current will ow from pin 8B to spring 42, to post 43, thence through Wire 45 to the supplementary pin 46 and to spring 5l, to post 52, and through Wire 53 to binding-post 54 without interfering with the delivery of alternating currents at binding-posts 39 and 37, and asuccession of positive pulsating currents are delivered at binding-post 54 and of negative pulsating currents at binding-post 5o, In the present state of the art of selective signaling the bells at the subscribers stations are usually connected to ground, their armatures being biased to respond only to positive or negative currents, and therefore by connecting a ground-wire to binding-post 39 the current will be alternately grounded on the positive and negative sides, so that the pulsating currents delivered at 50 and 54 Will ow from ground to the source of electricity, thence to line, and complete their circuits through the bells to ground. By means of this arrangement a single set of batteries will furnish both selective and alternating currents by successively grounding alternate poles of the battery.

I have found in practice that the complex circuits and the great nu mber of moving parts illustrated in Fig. l can be in a measure dispensed with, and in the development of the invention I have greatly improved and simplitied it, while still adhering strictly to the principle of my invention. Thus in Fig. 2 I illustrate a very much simpler device for delivering a series of pulsating direct positive and negative currents. In Fig. 2, 55is a cylinder of insulating material which is mounted on a shaft 56. This shaft is supported in bearings 57. These bearings are secured to standards 58, which are arranged at the sides of the cylinder. Three commutator-segments 59, 60, and 6l are arranged in alternate order,

with two insulated irregular-shaped ring portions 62 and 63, that are mounted on the cylinder between the commutator-rings. Each one of the commutator-segments consists of a cylinder of conductive material and is of a right-angled outlinethat is, one half is wider than the other half-and thus a rightangled form of outline is given to each ring. The insulated rings 62 and 63 are also of right-angled form or outline. This cylinder is preferably rotated by a small electric-battery motor 64, which is also mounted on an extension of the shaft of the cylinder, but may i IOO IIO

be rotated, if preferred, by a gas or steam enand from these binding-posts wires 72 and 73.

extend to brushes 74 and 75, which are arranged in operative relation to acommutator 76, that is mounted on the shaft 56 of the cylinder, which is operatively connected to the armature of the motor. I arrange in operative current-collecting relation to the cylinder seven brushes 77, 78, 79, 80, 81, 82, and 83. erably short pins of metal or carbon, which are supported slidably in suitable supports 84 and 85, arranged on opposite sides of the cylinder to stand at right angles to the axis of the cylinder. A conductive spring 86 is secured at one end to the base-plate below each brush, and the opposite end of each brush is arranged to bear resiliently against the outerend of its reciprocating pin. A wire 87 is connected to the spring of the brush 77 and leads to a binding-post C. A wire 88 extends from the spring of the brush 78 to a binding-post D. A wire 89 extends from the spring of the brush 79 to a binding-post E. A wire 90 extends from the spring of the brush 80 to the binding-post F. A wire'91 4 extends from the spring of the brush 81 to a binding-postG. A wire 92 extends from the spring of the brush 82 to a binding-post H,I

and a branch wire 93 is connected to the spring of the brush 83 and connects to the wire 90 ofthe brush 80. A battery 94 of preferably about fifty cells is connected to the binding-post C by a wire 95 and by a wire 96 to the binding-post D. The battery is connected so that the negative pole goes to C andthe positive pole to D. The ring 60 will then be permanently connected to the negative pole and the ring 61 will be permanently connected to the positive pole of battery, so that when the cylinder is revolved the brushes 79 and 80 will alternately collect positive and negative currents, which can be taken ofi? at E and F. As a branch connection extends from the brush 80 to the brush 83, then Whatever the polarity of brush 80 at any part of the revolution the polarity of the ring 59 will be the same, and this polarity will be communicated to brushes 81 and 82. In the position shown in the sketch and with the battery connected as stated above, brush 80 will be negative and brush 79 will be positive, and therefore the segment 59 will be negative, the brush 82 will deliver a negative current at H, and brush 8l will be insulated on the cylinder. When the cylinder revolves one half-revolution, brush.

80 will be positive and brush 83-will be positive, and thence ring 59 will be positive and will deliver a positive current to brush 81, thence to binding-post G, while brush 82 will be insulated on The cylinder. It will therefore be seen that this device furnishes alter- These brushes, as illustrated, are pref- `rents from the same commutator.

nating currents at binding-posts E and F and pulsating currents at Gr and H simultaneously and with one set of batteries. The currents from brush 79 must be grounded either at E or at the ringing-key, as desired, for selectiveV signaling.

While the device just described is much simpler than that shown in Fig. l, it does not represent my preferred construction, which lis shown in Figs. 5, 6, and 7, which while embodying all of the vital elements of the arrangement shown in Fig. 2 is still much simpler in construction and more direct in its operation. In the device shown in Figs. 5, 6, and 7 the cylinder 97 is of insulating material and is mounted on a shaft 98, which is supported in boxes 99, which are secured to suitable supports 100, and upon it there are mounted only two com mutation-segments 101 and 102,which are separated from one another by a non-conductive Z-shaped ring 103. These rings are all of right-angled outline the same as the rings in Fig. 2. One end of the shaft extends beyond its support and is shown broken off, but is intended to be connected to a battery-motor, as shown in Fig. 2, or it may be connected to and driven by any other suitable power. This cylinder, With its two commutation-segments and non-conducting ring, I term a compound com mutator, as it performs two distinct functions simultaneously with only two commutator-segments,

viz: Each ofthe brushes 108 and 109 alternately collects positive andV negative pulsat- IOO ing currents, while the brushes 104 and 105 are collecting and delivering alternating cur- I arrange in operative current-collecting relation these Vsix brushes 104, 105, 106, 107, 108, and 109. ,These brushes preferably compose pins of metal or carbon arranged at right angles to the axis of the' cylinder and are supported yslidably in insulated standards 110 at the opposite sides of the commutator. A conductive spring 111 is secured by a screw 112 to lthe base 1^, and its opposite end is arranged to resiliently bear Aagainst the end of each brush, and each brush is in contact with the comm utator. The two commutative rings are `arranged on opposite ends of the cylinder ,with their right-angled extension portions opposite each other, and the right-angled Z- shaped non-conductive `ring lies between them. vThe right-angled or extensionvportions are of little less than one-half of the ring in diameter, and commutation-segments are-'ary IIO ductive and non-conductive portions on each full half-revolution and are twice on the conductive or opposite sides of the commutator and twice on the non conductive. The brushes 106 and 107 are arranged to engage the outer ends of the commutators and are always in contact with theV commutators, while the brushes 108 and 109 are arranged to engage that portion of the right-angled eX- tension of the commntators that lies in the rotative path Of the opposite semicircular portions of the Z-shaped non-conductive ring. Consequently these brushes are alternately On the conductive portions at substantially one half of the revolution and on the nonconductive portion the other half of each revolution. A battery 113 is connected to a binding-post D by a wire 115 and also by a wire 116 to a binding-post F. From the spring of the brush 106 a wire 118 is extended to a binding-post D, and from the spring of the brush 107 a wire 119 is extended to a bindingpost F. From the brush 104 a wire 120 is run to a binding-post E, and from the spring of the brush 105 a wire 121 is run to a binding-post B. From the spring of the brush 108 a wire 1.22 is run to a binding-post C, and from the spring of the brush 109 a-wire 123 is extended to a binding-post A. The Operation is as follows: The commutator is kept constantly rotating by its motive power. A steady current iiows from the battery 113 and posts D and F to the brushes 106 and 107 and keeps the commutators 101 and 102 constantly charged. The brushes 104: and 105 as the commutator rotates deliver alternating currents at binding-posts B and E, and brushes 108 and 109 deliver pulsating positive and pulsating negative currents successively at binding-posts A and C, the operation being the same as that of the device in Fig. 2, except as to brushes 108 and 109.

The commutators in Figs. 2 and 5 are protected from dirt and dust by a cover 124, Which is shown only in Fig. 6 and which is arched over them and is secured to the supports of the brushes by screws 125.

It will be seen that my preferred construction of pole-changer embodying my invention is very simple in construction and arrangement, inexpensive to make, and not liable to get out of order and is positive and reliable in its action.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a pole-changer for transforming direct, constant, currents into alternating currents and pulsating currents of positive and negative polarity, the combination with the supporting-base, of a rotating cylinder provided with conductive ring portions having right-angled extensions oppositely disposed, a non-conductive ring portion between said conductive portions, brushes operatively arranged on said conductive and non-conductive ring portions to alternately engage said conductive and non-conductive ring portions of said cylinder, means for rotating said cylinder and means including a battery, terminal binding-posts, and connecting-wires for leading from said battery to said brushes whereby alternating currents are collected at a predetermined set of terminal binding-posts and for collecting direct pulsating positive and negative currents at other predetermined binding-posts substantially as described.

2. In a pole-changer for transforming direct, constant, currents into alternating currents and pulsating currents of positive and negative polarity, the combination with the supporting-base, of a shaft supported in suitable bearings,a commutation-cylindermounted on said shaft, an electric motor operatively connected to said shaft to rotate said shaft and commutation-cylinder, an electric battery arranged to operate said motor, and having said commutator comprise conductive rings, of a combined circular and right-angled outline arranged with their right-angled portion on opposite sides of said cylinder and to overlap each other in the rotative plane of said cylinder, and separated from one another by a non conductive ring portion, spring-controlled collecting-brushes arranged in contact with the circular part of each of saidconductive rings, terminal binding-posts arranged adjacent to said brushes, conductive wires connecting said binding-posts with said brushes, a battery connected to said terminal binding-posts and arranged and adapted to deliver a steady current to the circular portion of said conductive rings, a pair of brushes arranged in engagement with Opposite sides Of said commutator arranged in the rotative path of said right-angled overlapping portion of said conductive rings and of the intervening non-conductive ring portion alternately as said commutator rotates, terminal bin ding-posts arranged adjacent to said brushes and conductive Wires connecting said brushes to said terminal binding-posts, and brushes arranged in collective engagement with the relative path of the semicircular ring portion of said non-conductive rings, and of the semicircular right-angled portions of said conductive rings between the circular part of said conductive rings and the overlapping part of their right-angled extension portions, binding-posts adjacent to said brushes and conductive wires connecting said brushes to said binding-posts,substantially as described.

In testimony whereof I aiiix my signature in presence of two Witnesses.

JOHN CRAWFORD.

Witnesses:

G. SARGENT ELLIOTT, JOSEPH WILKINSON.

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